Sisneros signed a state party pledge to support the GOP's standard-bearer, but that was before Trump was the official nominee. He said one of his options is to resign, allowing the state party to choose another elector.

State electors meet in Austin and in state capitals nationwide next month to vote for president, and will also vote then on Sisneros' replacement.

Electors are chosen by party officials and are typically the party's most loyal members. Presidential electors are not required to vote for a particular candidate under the Constitution. Even so, the National Archives says more than 99 percent of electors have voted as pledged throughout the nation's history.